1. Field of the Invention
The present invention relates, in general, to masts for lift trucks and more specifically to a stacking mast for a marina fork lift truck.
2. Information Disclosure Statement
A preliminary patentability search in class 414, subclass 678, and class 187, subclass 9E, disclosed the following patents, some of which may be relevant to the present invention: Harris, U.S. Pat. No. 2,886,197, issued May 12, 1959; Crosby et al., U.S. Pat. No. 3,029,959, issued Apr. 17, 1962; Peck, U.S. Pat. No. 3,174,634, issued Mar. 23, 1965; Pusztay, U.S. Pat. No. 3,330,383, issued July 11, 1967; McIntosh, U.S. Pat. No. 3,433,324, issued Mar. 18, 1969; Wilson, U.S. Pat. No. 3,602,385, issued Aug. 31, 1971; Erickson et al., U.S. Pat. No. 3,841,442, issued Oct. 15, 1974; Soule et al., U.S. Pat. No. 4,485,894, issued Dec. 4, 1984; Griesenbrock et al., U.S. Pat. No. 4,506,764, issued Mar. 26, 1985; and Tworoger et al., U.S. Pat. No. 4,797,055, issued Jan. 10, 1989. Additionally, during prosecution of the predecessor to this application, the following patents were cited: Arnot et al., U.S. Pat. No. 2,767,394, issued Oct. 16, 1956; Guerin, U.S. Pat. No. 2,399,632, issued May 7, 1946; Bentivoglio, U.S. Pat. No. 4,889,038, issued Dec. 26, 1989; and Burton, U.K. Patent No. 640,138, published July 12, 1950. While each of the above patents disclose a mast or the like, none disclose or suggest the present invention. More specifically, none of the above patents disclose or suggest a stacking mast including, in general, an elongated first mast, the first mast including a lower end for being attached to the lift truck and including an upper end; an elongated second mast, the second mast including a lower end and an upper end; a floating carriage means for securing the second mast to the first mast, the floating carriage means including first securing means for being slidably secured to the first mast and including second securing means for being slidably secured to the second mast; a support carriage slidably attached to the second mast for supporting the load; an lift means for moving the support carriage between a lower position and an upper position on the second mast and for moving the second mast between a lower position and an upper position on the first mast. In particular, Arnot et al., U.S. Pat. No. 2,767,394, while showing a lift truck with a first and second mast, has no floating carriage means for securing the second mast to the first mast which is slidably secured to the front mast and also slidably secured to the second mast.